I saw this well-written discussion of the science of cloud seeding this morning and thought you might be interested. Cloud seeding is the injection of specific chemicals into clouds to help them form precipitation. It is often discussed as a way of helping farmers get more rainfall, especially in times of drought. But if you don’t have enough moisture or the right kind of clouds, it can actually cause more harm than good. You can read about it at Mother Nature News at https://www.mnn.com/earth-matters/climate-weather/stories/what-cloud-seeding. Cloud seeding can also create cool clouds like this hole-punch cloud pictured below, which is caused by ice crystals from higher clouds or contrails falling into a cloud layer and causing local precipitation in the form of snow.